Use an external Syslog tool like Splunk. Store it there and analyze it.
See link in my signature on how to get it up and running.
http://forum.mikrotik.com/t/tool-using-splunk-to-analyse-mikrotik-logs-3-3-graphing-everything/121810/1
PS
If you post your current OSPF logs, I may be able to add a view for it in Splunk